Field of the Invention
The present invention relates to cleaning compositions and, more particularly, to strong acid-based cleaning compositions. Specifically, the present invention relates to an aluminum cleaner and brightener composition having a pH value of less than 1.0, yet is nonreactive and nonirritating to human skin tissue.
Description of the Prior Art
Numerous compositions and processes have been employed in the past for the purpose of brightening and cleaning residue, deposits and impurities from aluminum surfaces. Various abrasive techniques have also been used in the past, such as scrubbing, scouring, use of steel wool, sand blasting and the like, for the purpose of removing such materials. In addition, chemical compositions ranging from degreasers and detergents to extremely corrosive acid baths and caustic chemicals, which are difficult and messy to apply, have been used for various shower and bathroom cleaning applications.
Examples of acidic compositions which have been utilized for a wide variety of cleaning applications include U.S. Pat. Nos. 4,675,120, 3,514,407, 3,630,933, 4,116,713, 4,181,622, 4,199,469, and 4,250,048. While many of these referenced patents are not specifically designed for cleaning aluminum and the like, they do disclose acid-based compositions for the purposes of cleaning a wide variety of different types of surfaces. One unfortunate and significant disadvantage of many of these acid-based cleaning compositions is that while they are effective cleaning agents, they can be extremely corrosive and highly reactive with human skin tissue as well as other compositions having relatively low oxidative states. U.S. Pat. No. 4,477,364 discloses an acidic glass cleaning composition which has a low pH value for cleaning yet is relatively innocuous to skin tissue. However, this particular disclosure is directed only to the specific challenges relating to the cleaning of glass surfaces and is so limited thereto.
Abrasive cleaning methods tend to be only temporarily effective and are very destructive and physically tiresome, and the abrasion process tends to scratch the surface being cleaned, thereby removing its natural luster. Moreover, abrasive cleaning tends to be inconsistent in removing excess material from the surface being cleaned and also tends to remove excess metal in some areas and not in others thereby eroding the metal beyond acceptable tolerances. While soaps and degreasing solutions eliminate oil and grease build-up, they generally have negligible effect on oxides and surface discoloration. Moreover, acid-based cleaning solutions tend to react violently with the different aluminum alloys, and the pH values of acid-based cleaning solutions must be carefully controlled to avoid excessive corrosion and damage to the metal surface. The pH values of acid-based cleaning solutions must be low enough to provide the desired oxidation for cleaning, yet it must be sufficiently mild enough to permit ease of handling. Otherwise, strong acid-based solutions require special handling techniques and equipment not readily available to the average household user.
As a result of the above, there is still a need for an effective cleaning and brightening solution particularly applicable to aluminum surfaces such cleaners having requirements different from those of cleaning agents for other types of material surfaces and applications. Such a cleaning composition need not be abrasive, and should be effective in removing residue, deposits and impurities, non-corrosive to the aluminum surface being cleaned, and non-reactive with human skin tissue to permit easy and safe use by individuals applying the solution.